Unlucky Dave,
I filled in new paperwork for the company vehicle insurance a few months ago, on it was a reference to a crash where someone went into the back of the van at a roundabout (my engineer was driving) I have had over 20 "no win no fee" you didn't make an injury claim calls from various companies - none of them my insurer! Even had one offering to make a claim against a 4 year old bump when no one was in our van it was parked on the side of a road ?????
No doubt the same thing has happened to the driver and he has said yes - I'm sure when they find out the claim was settled with you not at fault they will drop it. - Or at least I hope so, bloody PITA things like this we had to fill in a shed load of paperwork when someone wrote down a wrong number plate on a form and the insurance company came after us - we were 20 miles away when the crash happened
Hope you get it sorted mate